Ultrasound-assisted green bromination of N-cinnamoyl amino acid amides - Structural characterization and antimicrobial evaluation
Abstract
N-phenylpropenoyl amino acid amides have been brominated using two alternative sonochemically activated green chemistry procedures. The first synthetic procedure has involved an ultrasound assisted bromination in an aqueous medium using ionic liquid as a catalyst of the reaction, whereas in the second one an in situ formation of Br(2) via oxidation of HBr by H2O2 has been used.
For comparison, the conventional bromination procedure was also used. The newly brominated compounds were characterized by appropriate analytical techniques.
A detailed NMR spectroscopic analysis and quantum chemical calculations using Density Functional Theory (DFT) methods have been used to define the stereochemistry of the products. The results confirmed the physicochemical identity and similar yields of the products obtained by the three synthetic procedures employed, and reveal the co-existence of two diastereoisomeric forms of the newly synthesized products.
The antibacterial and antifungal activities of the dibrominated amides were evaluated.